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Discussion Starter #1
I discovered that my rear locker wasn't working yesterday while out on a trail run. 4Low works, (verified) as well as ATRAC. (also verified) The locker light will come on and blink constantly, but the locker never engages.

I performed the "locker on demand" hack a few years back, so I suspected that. I double checked everything, and nothing appeared amiss. Just to eliminate that as a possibility, I converted everything back to stock. No luck there. Everything works and lights up, but the locker doesn't engage. For what it's worth, the mod *did* work when I first tried it. I rarely use my locker out on the trail, so I'm not sure when this problem of non engagement actually started.

After cleaning the truck, I decided to check out the locker itself. Nothing looked damaged. I pulled both connectors from the top of the unit and cleaned them with electronics cleaner. I placed the truck in 4Low, engaged the locker, and probed the connectors for power. No power at the connectors. I slowly crept back and forth along the street, but nothing happened with the locker.

That's as far as I got with it. I'm pretty sure I'm supposed to see power at those connectors if all the conditions are met. (4Low engaged, locker switch on) I can get 4High, 4Low, and ATRAC to work, so I think it's isolated to the locker itself. Can anyone help me troubleshoot this issue further? Is there any way to test the locker motor itself to see if it's the culprit? Any ideas/suggestions welcomed and appreciated! Mahalo for your help!
 

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I discovered that my rear locker wasn't working yesterday while out on a trail run. 4Low works, (verified) as well as ATRAC. (also verified) The locker light will come on and blink constantly, but the locker never engages.

I performed the "locker on demand" hack a few years back, so I suspected that. I double checked everything, and nothing appeared amiss. Just to eliminate that as a possibility, I converted everything back to stock. No luck there. Everything works and lights up, but the locker doesn't engage. For what it's worth, the mod *did* work when I first tried it. I rarely use my locker out on the trail, so I'm not sure when this problem of non engagement actually started.

After cleaning the truck, I decided to check out the locker itself. Nothing looked damaged. I pulled both connectors from the top of the unit and cleaned them with electronics cleaner. I placed the truck in 4Low, engaged the locker, and probed the connectors for power. No power at the connectors. I slowly crept back and forth along the street, but nothing happened with the locker.

That's as far as I got with it. I'm pretty sure I'm supposed to see power at those connectors if all the conditions are met. (4Low engaged, locker switch on) I can get 4High, 4Low, and ATRAC to work, so I think it's isolated to the locker itself. Can anyone help me troubleshoot this issue further? Is there any way to test the locker motor itself to see if it's the culprit? Any ideas/suggestions welcomed and appreciated! Mahalo for your help!
OK, all you really know is that the E-locker control electronics (the 4WD ECU) is not receiving a signal confirming that the E-lock mechanism has actually moved to the "locked" position.

That fact that the E-locker light on the instrument panel is flashing indicates that the E-locker control electronics "thinks" it has sent a "LOCK" command to the rear axle, and is waiting for the E-lock position switch to confirm that the locker has actually locked.

Your "test" at the E-locker connectors may have deceived you, as the E-locker motor is controlled by the 4WD ECU and may NOT provide a permanent +12V signal at any connector pin. The only thing I can guarantee is that the WHITE wire with the BLACK stripe provides system ground to the entire E-locker assembly on the RR diff, and this must show continuity to chassis ground (much less than 1 ohm).

Notwithstanding your "power at the connector" test, the E-locker will almost never lock on pavement when driving straight ahead. Before concluding that you have any problem with the E-locker or its control system, go back out and slowly drive forward while repeatedly turning the steering wheel ~1 turn left and then 1 turn right from the straight-ahead position. For the E-lock mechanism to physically lock, there must be some small speed differential between the L and R axles; driving the undulating path forces this speed difference. (If this does get the E-locker to lock, immediately disengage it; DON'T attempt to turn on pavement with the axle locked!)

If that doesn't help, next step would be to triple-check ALL the wiring associated with your "on-demand" hack of the E-lock control system. Make sure all the original wiring has been reconnected properly, any "splices" have been soldered and not just crimped, etc.

If that doesn't help, you are going to need to do some continuity testing of the wiring back to the E-locker. Do you have a copy of the relevant schematics? On my copy of the 2007 Electrical Wiring Diagram, the E-locker wiring is shown on page 196.
 

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Discussion Starter #6
I don't know if it does have its own fuse.. but I'm sure its fused somewhere, even if it is tied in with something else.
Basil,

I found the fuse inside the cabin, driver's side, under a cover down by knee level of the dash. Fuse tested good, so that's not it.
 

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Discussion Starter #7
OK, all you really know is that the E-locker control electronics is not receiving a signal confirming that the E-lock mechanism has actually moved to the "locked" position.

That fact that the E-locker light on the instrument panel is flashing indicates that the E-locker control electronics "thinks" it has sent a "LOCK" command to the rear axle, and is waiting for the E-lock position switch to confirm that the locker has actually locked.

Your "test" at the E-locker connectors may have deceived you, as the E-locker motor is controlled by the 4WD ECU and may NOT provide a permanent +12V signal at any connector pin. The only thing I can guarantee is that the WHITE wire with the BLACK stripe provides system ground to the entire E-locker assembly on the RR diff, and this must show continuity to chassis ground (much less than 1 ohm).

Notwithstanding your "power at the connector" test, the E-locker will almost never lock on pavement when driving straight ahead. Before concluding that you have any problem with the E-locker or its control system, go back out and slowly drive forward while repeatedly turning the steering wheel ~1 turn left and then 1 turn right from the straight-ahead position. For the E-lock mechanism to physically lock, there must be some small speed differential between the L and R axles; driving the undulating path forces this speed difference.

If that doesn't help, next step would be to triple-check ALL the wiring associated with your "on-demand" hack of the E-lock control system. Make sure all the original wiring has been reconnected properly, any "splices" have been soldered and not just crimped, etc.

If that doesn't help, you are going to need to do some continuity testing of the wiring back to the E-locker. Do you have a copy of the relevant schematics? On my copy of the 2007 Electrical Wiring Diagram, the E-locker wiring is shown on page 196.
FJtest,

Thanks for the reply!
I am pretty familiar on how the locker engages, and I was doing as you described yesterday while trying to get the locker to engage. I would try to repeat this today, but I need an area other than pavement to do so. I agree that the locker will almost never engage while going in a straight line. I will need to re-verify this once I find an area to do my test.
The locker mod I performed involved the cutting of one wire. I reconnected this wire back to stock by using solder and heat shrink. The simplicity of the mod is one of the reasons I took a chance and did it. I know it worked after I did it the first time, so I know I didn't cut the wrong wire.
I kind of thought that my "test" may have been too simplistic in nature, but I thought that 12 volts would have been present somewhere to provide power to the locker.
I do have a copy of the Elocker electrical diagram, but I may need some help performing the continuity tests. Electronics is not really my forte. lol Thanks for your help so far!
 

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Discussion Starter #8
I found a small field near my house to try to engage the locker. I went left, right, complete circles, and figure eights to no avail. I also tried doing some stuff in reverse as well. No luck. I got 4Low and ATRAC, but the locker never engaged.
I guess things get more complicated. <sigh>
 

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I found a small field near my house to try to engage the locker. I went left, right, complete circles, and figure eights to no avail. I also tried doing some stuff in reverse as well. No luck. I got 4Low and ATRAC, but the locker never engaged.
I guess things get more complicated. <sigh>
OK, lets move on to the "simple" electrical testing. This will probably require two people, or some long extension wires.

1. Climb back under the rear axle, and unplug the 2-pin "motor" connector from the E-locker. This will be the connector with the RED wire with BLACK stripe, and the RED wire with BLUE stripe.

2. Carefully connect a 12V test lamp or a digital multimeter to the two contacts in the connector. Do not stick anything hard into the contacts that would deform them, but you must make sure that good electrical contact is made. If you stay under the vehicle to monitor the test lamp or meter, have someone press the E-lock button when you yell. You must be watching the meter/test lamp continuously, as the 4WD ECU may only send a short duration current pulse to the motor.

3. Shift transfer case into 4L range.

4. Turn ignition on.

5. Yell at your assistant to press the E-lock button.

6. If you see 12V appear on the meter, or the lamp illuminates, then you know the 4WD ECU is sending a LOCK command to the E-locker motor. Then, the next steps will be to see why the motor (apparently) doesn't run. If you don't see any indication of 12V, then more electrical troubleshooting will be required.

A few other misc thoughts:

a) What year FJ is this?

b) Do you ever drive through hub deep water?

c) If so, do your RR diff and E-locker have the original breather setup (not extended)?

d) Before starting on the more comprehensive electrical troubleshooting, you might also try supporting the rear axle on jackstands, shift into 4L, turn on the ignition, trigger the E-lock button, and have someone turn one of the rear wheels while you firmly rap the E-locker housing with a plastic-faced hammer. This might jar the innards into motion if something is just mildly stuck.
 

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Anyone else thinking to themselves... "damn, we sure are lucky to have members here with the amount of knowledge that they do!"
@FJtest and quite a number of other members are invaluable to us "average joes"

Here's to you guys with the expertise that help the rest of us out all the time!!
:cheers:


(sorry for the threadjack, carry on)
 

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Discussion Starter #11
I hear ya, Winterpeg! That's why I love this forum.

FJtest,

Just to answer your questions: I have a 2007 TRD. Yes, I have drove through hub-deep water, and yes, I have extended all of my breathers. (SCUBA mod)

I will try the tests you described above and report back with the results. Thank you so much for trying to help me. It's frustrating not knowing the exact reason why something doesn't work.
 

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Discussion Starter #12 (Edited)
FJtest,

I tried doing the simple test you described earlier. My two pin connector didn't have the wire coloring you described, but it was one of only two electrical connectors going to the elocker motor.The other one appeared to have 5 pins. Anyhow, I had my helper push the button with the ignition on and in 4low.
I didn't get any voltage on my test light, but my partner said that when I grounded on of the pins the locker light would stay on solid. (Not blinking) Thoughts?
 

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Discussion Starter #13 (Edited)
Just another thought, could it be a possible faulty relay for the no power issue?
I'll put her up on stands and try the other method you described tomorrow. Thanks again!
 

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FJtest,

I tried doing the simple test you described earlier. My two pin connector didn't have the wire coloring you described, but it was one of only two electrical connectors going to the elocker motor.The other one appeared to have 5 pins. Anyhow, I had my helper push the button with the ignition on and in 4low.
I didn't get any voltage on my test light, but my partner said that when I grounded on of the pins the locker light would stay on solid. (Not blinking) Thoughts?

(NOTE: Reviewing the schematic again, I think I told you the wrong connector pin count. The two-pin connector is for the position feedback switch , while the 5-pin connector should have the "RED/BLACK" and "RED/BLUE" wires that drive the motor. Unfortunately, the Toyota schematics don't clearly show the connector housings or their pin count.)


1. When you got the E-lock indicator light to stay on solid, I'm sure you were grounding the "BLUE WITH YELLOW STRIPE" wire. This wire is goes to the position feedback switch in the E-locker that tells the 4WD ECU that the mechanism has moved to the "locked" position. By grounding that pin of the connector, you "simulated" the feedback switch being in the "locked" position. The real switch connects the BLUE/YELLOW wire to ground when the axle is locked. So, you at least know that the wiring for the position sensing switch is intact back to the 4WD ECU.

3. Do whatever is necessary to locate the "RED/BLACK" and "RED/BLUE" wires in the 5-pin connector. You're going to have to find the wires with the EXACT color coding shown on the schematic. You may have to peel back the tape at the end of the protective sleeving near the connectors, & carefully clean the wires to be able to see the wire color. Most of the wires will have a solid body color plus a thin colored stripe. You'll be absolutely working blind if you can't determine the wire color coding.


4. Perform the "power present" test I described in the previous post, making sure that you are looking for voltage across the RED WITH BLACK STRIPE and RED WITH BLUE STRIPE wires.

5. If you find that 12V is present at the connector, even momentarily, then check the integrity of the connector chassis grounds, from the connector ground pins to a clean. bright bare metal spot on the chassis..

If possible, use a multimeter to confirm that the ground connections for the E-locker are good. Your FJ is an older one, and the ground connections to the body shell may be corroded or the clamp bolts may not be as tight as they once were.

Find the BLACK or WHITE WITH BLACK STRIPE wires coming out of BOTH connectors, and verify that the resistance to chassis ground is much less than 1 ohm. You'll need a good quality digital multimeter to measure this low a resistance, a $6 Harbor Freight meter won't cut it.

But first, let us know if you see 12V when you locate the RED/BLACK and RED/BLUE wires.
 

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Discussion Starter #15
(NOTE: Reviewing the schematic again, I think I told you the wrong connector pin count. The two-pin connector is for the position feedback switch , while the 5-pin connector should have the "RED/BLACK" and "RED/BLUE" wires that drive the motor. Unfortunately, the Toyota schematics don't clearly show the connector housings or their pin count).


1. When you got the E-lock indicator light to stay on solid, I'm sure you were grounding the "BLUE WITH YELLOW STRIPE" wire. This wire is goes to the position feedback switch in the E-locker that tells the 4WD ECU that the mechanism has moved to the "locked" position. By grounding that pin of the connector, you "simulated" the feedback switch being in the "locked" position. The real switch connects the BLUE/YELLOW wire to ground when the axle is locked. So, you at least know that the wiring for the position sensing switch is intact back to the 4WD ECU.

3. Do whatever is necessary to locate the "RED/BLACK" and "RED/BLUE" wires in the 5-pin connector. You're going to have to find the wires with the EXACT color coding shown on the schematic. You may have to peel back the tape at the end of the protective sleeving near the connectors, & carefully clean the wires to be able to see the wire color. Most of the wires will have a solid body color plus a thin colored stripe. You'll be absolutely working blind if you can't determine the wire color coding.


4. Perform the "power present" test I described in the previous post, making sure that you are looking at the voltage on the RED/BLACK and RED/BLUE wires.

5. If you find that 12V is present at the connector, even momentarily, then check the integrity of the connector chassis grounds, from the connector ground pins to a clean. bright bare metal spot on the chassis..

If possible, use a multimeter to confirm that the ground connections for the E-locker are good. Your FJ is an older one, and the ground connections to the body shell may be corroded or the clamp bolts may not be as tight as they once were.

Find the BLACK or WHITE WITH BLACK STRIPE wires coming out of BOTH connectors, and verify that the resistance to chassis ground is much less than 1 ohm. You'll need a good quality digital multimeter to measure this low a resistance, a $6 Harbor Freight meter won't cut it.

But first, let us know if you see 12V when you locate the RED/BLACK and RED/BLUE wires.
Understood. I'll report back with my findings after I repeat the test. Thank you again!
 

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Not to direct you away from the testing that you are doing with FJtest, but I just went through something similar. Exact same symptoms. Here are my posts. Just thought that they may help
Have you thought about pulling your locker and putting the rig on stands, then engaging your locker to see if it works?

http://www.fjcruiserforums.com/forums/transmissions-transfer-cases-traction-aids/296722-another-rear-diff-lock-not-working.html

http://www.fjcruiserforums.com/forums/transmissions-transfer-cases-traction-aids/402650-e-locker-actuator-removal-help.html

I know that you live in Hawaii, however is there a possibility of salt water corrosion?

Pup
 

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Not to direct you away from the testing that you are doing with FJtest, but I just went through something similar. Exact same symptoms. Here are my posts. Just thought that they may help
Have you thought about pulling your locker and putting the rig on stands, then engaging your locker to see if it works? (snip)
From post #9 of this thread:

"Before starting on the more comprehensive electrical troubleshooting, you might also try supporting the rear axle on jackstands, shift into 4L, turn on the ignition, trigger the E-lock button, and have someone turn one of the rear wheels while you firmly rap the E-locker housing with a plastic-faced hammer. This might jar the innards into motion if something is just mildly stuck."
 

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Sorry FJTest, I was more meaning to pull the locker when up on jack stands to see if the gear on the locker turns. Thats how I was able to decipher my problem because I am electrically challenged. It won't tell you if there is an electrical problem, it was just suggested to me in one of my attached posts as a troubleshooting aid.
Your post would definitely precede my suggestion.

Pup
 

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Discussion Starter #19
Pup,

No worries. In fact, I read your threads carefully after experiencing my problem. If the latest suggestion from FJtest doesn't pan out, I'm planning on doing what you have mentioned.
I really don't think that corrosion could be the issue, but you never know. My rig is a 2007, but I only have 25K miles on her.
Thanks for the suggestion though, pup. I really appreciate the help. I'm going to continue troubleshooting in a bit. I'll post my findings.
 

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Discussion Starter #20
FJtest,

I just finished taking my readings. I had to sand a small area on the frame down to bare metal to create a good ground and get consistent readings. Here's what I found:

Ignition on, 4Low engaged:

Red/Blue stripe: Button off: 3.2mv, Button on: 6.3mv

Red/Black stripe: Button off: 3.2mv, Button on: 6.2mv

Ground:

2 pin connector: 1.8 ohm

5 pin connector: 1.8 ohm

It appears that I'm not getting power to the motor when the button is pressed. This leads me to believe that something upstream is amiss. A relay, maybe?
Should I continue on with the other mechanical test (wheels up, tapping locker housing) or is further electrical troubleshooting recommended?
Thanks!

Steve
 
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